Samuel Campos, 23, walked into the law enforcement center this morning to turn himself in.
He reportedly told officers he knew there was a warrant for his arrest and that he tried to call detectives a couple of times before turning himself in.
Police arrested 33-year-old Ruben Juarez on Monday for the same aggravated assault, an incident that happened last Thursday night at North 13th and Orange.
Juarez and Campos reportedly attacked the victim when he got out of his car on Orange street last week, sending him to the hospital where he has been unresponsive ever since.
He is now in a medically-induced coma.
Both men were taken to the Taylor County Jail.